The research has been made to establish the heteroepitaxial growth technique for LiNbO_3 (LN) optical-waveguide film by UV laster ablation (or laser deposition), followed by forming electrooptic (EO) modulators/switches in the resulting film. The research should be applied for a novel functional optical interconnection of Si-ICs. Major research results are described in the following.1. We have confirmed, for the first time, that the ArF excimer laser ablation is a suitable technique for epitaxial growth of electrooptic waveguide film on C-cut sapphire.2. The deposited LN film is almost stoichiometric with well orientation along the C-axis under the condition that a Li-rich LN ceramic disk is used as the target where the Li/Nb ratio is 2.1. The droplet-free LN film is also grown only by increasing the target-to-substrate distance to 40mm without remarkable reduction of the deposition rate.3. The Bragg light deflector was fabricated to evaluate the EO coefficient r33 in the resulting LN film. r33 was found to be as large as 4.9pm/V,which was nearly one sixth of the single-crystal value. The obtainable value of r33 is large enough for optical modulation and switching in the LN film.4. In addition, Nd-doped LN film was deposited on sapphire to form waveguide lasers/amplifiers. The deposited film was well-oriented along the C-axis with the almost same chemical composition as the single crystal, although the film surface was remarkably rough.5. On the basis of the experiment described above, the functional optical interconnection of Si-ICs was discussed theoretically, in which channel waveguides were formed by partial dielectric loading on the LN film for optical modulation and switching, and the optical path change was performed with relief gratings of TiO_2 film.